The present invention relates to a transportation device, especially a wheelchair, having a braking system comprising a locking brake, as well as a method for locking said transportation device.
The invention will be described in the following in conjunction with a wheelchair. This description should, however, not be understood in any way as a restriction to the application of the invention. On the contrary, the invention is also applicable to other transportation devices provided with wheels, etc., and having at least one rotating wheel.
A wheelchair with a locking brake is already known in which a locking force is exerted on at least one air-filled tire of the wheelchair by way of a manually actuated toggle lever such that said tire is substantially non-rotatably coupled to the supporting parts of the wheelchair.
The arrangement of such a toggle brake on a wheelchair represents a suitable measure for preventing an undesired rolling movement of the wheelchair in certain situations. For example, in many situations the rolling of a manned or unmanned wheelchair on an incline can be prevented with a set toggle brake.
However, the braking power of such a wheelchair having a toggle brake depends to a not insignificant degree on the air pressure in the tires. Thus, a toggle brake adjusted for a tire with, for example, high air pressure exerts a lower braking force on the wheelchair when the tires actually have a lower air pressure. There is obviously a considerable degree of danger inherent in such diminished braking power. Especially if the wheelchair is manned, there is a danger that a user can inadvertently put his wheelchair into motion, which can result in a situation where the wheelchair user, not expecting this rolling movement, is not in command of the traffic situation or does not have sufficient control over the wheelchair and crashes.
Since those in wheelchairs are generally restricted in the ability to move their limbs, such a crash can cause significant injuries to the wheelchair user, which in particular is also due to the fact that the wheelchair user, restricted in his mobility, cannot necessarily support himself to a sufficient extent. In an unfavorable situation, there is the danger that a crash could occur with another user of the road. Thus, for example, the known wheelchairs with toggle brakes do not rule out a situation in which the wheelchairxe2x80x94manned or unmannedxe2x80x94rolls into a street and is struck there by a moving vehicle. In addition to any material damage, other road users could also suffer physical injuries.
Consequently, the task of the present invention is to provide a transportation device for bodies, such as a wheelchair, which has a simple construction and can be manufactured economically and having a brake such as a parking or locking brake which ensures a high degree of traffic safety based on high braking reliability being independent of uncontrollable operational parameters of the transportation device.
This task is solved in accordance with the present invention by a transportation device for bodies according to claim 1.
The inventive method for locking a transportation device is the object.
Preferred embodiments of the invention constitute the subject matter of the subclaims.
The present invention thus provides for a transportation device for bodies having a braking system in which the braking force exerted is essentially independent of the elasticity of the tires of said transportation device.
The braking system preferably comprises a lockable braking means and provides for same as an especially preferred embodiment.
Since tire elasticity can be, for example, a contingency based on the fact that the tires are filled with air, respectively that the tires comprise an air-filled tube, the braking power according to the present invention is preferably essentially independent of the air pressure within the tube.
The transportation device, for example a wheelchair, a bicycle trailer, a tricycle, a Kettcar (push-pedal chain gear operated vehicle) or the like, comprises a frame means. The term xe2x80x9cframe meansxe2x80x9d is to be broadly interpreted here and includes in particular a tubular construction or any other such related supporting construction. A receiving means for receiving a body is integrated directly or indirectly into said frame means. A body is, for example, an inanimate object or a human body.
At least two moveable wheels are opposingly arranged on the frame means. These wheels, supporting for example a tire which is preferably an outer casing-tube arrangement, have a radially inward situated hub disposed to be moveable at least intermittently relative the frame.
At least three wheels are preferably provided; at least four are particularly preferred. Preferable in this case is that some of said wheels comprise the above-mentioned hub. Especially preferred are all of said wheels having the above-mentioned hub.
An axle is disposed situated concentrically inside the hub, arranged concentrically around a central axis. Said axle preferably projects out from the hub; especially preferable is the axle running through the hub such that it axially projects out of same at both hub ends.
It is preferable for one axle to extend into at least two hubs; especially preferred is that each hub is allocated to just one axle.
Said axles are at least partially fixedly arranged relative the frame means. Preferably, the axles are supported directly and/or indirectly on the frame means at both sides of same. Especially preferred is the one-sided, meaning unilateral, supporting of the axles directly and/or indirectly to the frame means.
Especially preferred is the disposing of at least one bearing, such as a radial bearing and/or axial bearing and/or radial-axial bearing or the like, between the axle and the hub.
The transportation device further has a gearing means for receiving a signal for the triggering or terminating of at least one braking and/or locking procedure. The term xe2x80x9csignalxe2x80x9d is to be understood here in a broad sense. A signal in the sense of the present invention is, for example, a torque or a force, a pivotal or a helical movement. The signal is preferably of mechanical or hydraulic type. Especially preferred is an electrical or electromagnetic or pneumatic signal. Preferably, this signal is initiated by a Bowden cable and/or a rotary knob and/or a control lever and/or an eccentric means.
According to a preferred embodiment of the present invention, the braking system has at least a first and at least a second contact surface area. The first contact surface area is at least intermittently essentially non-rotatably coupled relative the central axis with a wheel. The second contact surface area is at least intermittently essentially non-rotatably coupled relative the central axis with the frame. It is hereby preferred that at least one of the above-cited non-rotatable couplings be released when the brake is in an unlocked position. It is especially preferred that the non-rotatable couplings are also in place when the brake is in a released position.
Said contact surface areas are distinguished in that they at least partially position upon one another upon an actuated brake and/or locking brake.
Preferable is having at least one of said contact surface areas being arranged moveable relative the wheel, respectively relative the frame, thus for example axially displaceable. Especially preferred is that at least one of said areas is arranged fixedly relative the wheel, respectively frame.
It is preferred to reduce the existing torque difference between the wheel and the frame with respect to the central axis when the first contact surface area is non-rotatably coupled to the wheel and the second contact surface area is non-rotatably coupled to the frame relative the central axis and these contact surface areas are in at least partial contact with one another.
Especially preferred is the preventing of a torque difference between the wheel and the frame with respect to the central axis when the first contact surface area is non-rotatably coupled to the wheel and the second contact surface area is non-rotatably coupled to the frame relative the central axis and these contact surface areas are in contact with one another. Especially preferred is the torque difference between the frame and the wheel in the above-described engagement relationships then being almost at zero when, for example, an external torque is applied to the wheel which is less than a predetermined ceiling torque.
According to an especially preferred embodiment of the present invention, this ceiling torque is adjustable. The ceiling torque, which is fundamentally adjustable to any value desired can, for example, be dependent upon material parameters, the design of individual or several components, a compressive force applied to the contact surface areas, etc.
According to a preferred embodiment of the invention, the respective contact surface areas are disposed external the tire. In this context, xe2x80x9cexternal the tirexe2x80x9d is to be understood as that none of the contact surface areas are arranged on the tire. The wheel preferably has a rim which is connected to the hub by means of, for example, an arrangement of spokes. It is hereby especially preferable that the contact surface areas are arranged external the rim. The term xe2x80x9cexternalxe2x80x9d is to be understood here as in the above-described sense.
According to a particularly preferred embodiment of the present invention, the braking system and/or the locking brake means is arranged at least partly within the hub. For example, the braking and/or locking brake means is arranged radially inside of the radially outward situated contour of the hub. Arranging the braking and/or locking brake means radially inside of the radially inner situated contour of the hub is also especially preferred.
In accordance with a particularly preferred embodiment of the present invention, the contact surface areas are arranged radially inward the radially inner and/or radially outer situated surface contour of the hub walling.
xe2x80x9cInside ofxe2x80x9d is hereby preferably to be understood as that the axial position of the braking system and/or the locking brake means and/or the contact surface area is not restricted. Especially preferred when interpreting xe2x80x9cinside of,xe2x80x9d however, is that the braking means and/or the locking brake means and/or the contact surface areas is/are also arranged axially inside the hub at least partially, preferably completely. It is preferred in an embodiment that the braking system and/or the locking brake means and/or the contact surface areas be arranged at least partiallyxe2x80x94completely is especially preferredxe2x80x94inside a (fictitious) cylindrical region which extends about the central axis and where the radius of same is defined by the distance between the central axis and the maximum radially external point of the hub.
As an example, this point is a point arranged radially external on a radially extending flange of the hub. Such a flange is disposed with, for example, holes for the reception of spokes.
Another embodiment enables parts of the braking system and/or the locking brake, respectively parts of the contact surface areas, to have a greater radial spacing from the central axis than the point of the hub having the greatest radial distance from the central axis.
In an especially preferred embodiment of the present invention, the braking system and/or the locking brake means and/or the contact surface areas is/are at least partly arranged directly between the axle and/or a first intermediate means connected with the axle at least intermittently essentially non-rotatable relative said central axis and the hub and/or a second intermediate means connected with the hub at least intermittently essentially non-rotatable relative the central axis.
To give an example, elements are thus arranged between the hub and the axle which allow the realizing of a non-rotatable connection between the frame and the wheel; said elements are hereby not incorporated in the frame and/or the areas of the wheel which lie external or outside of the hub.
Especially preferred is the arranging of a contact surface area on the hub and/or a contact surface area on the axle.
It is also preferred that the braking system and/or the locking brake means and/or the contact surface area is/are axially arranged at least partially, preferably completely, external the hub.
According to an especially preferred embodiment of the invention, the first contact surface area is arranged on at least a first element and the second contact surface area is arranged on at least a second element which differs from said first element. Particularly preferred is that these elements, these contact surface areas respectively, can be coupled at least partly by means of a frictional contact connection such that said first element is essentially non-rotatably coupled to the second element upon actuated locking brake, respectively the torque difference between- the first and the second element is reduced upon actuated braking means.
Preferably a cone-shaped, respectively a tapered cone-shaped inner surface arranged on the first and/or second element engages in a cone-shaped or a tapered cone-shaped outer surface arranged on said first and/or second element.
Especially preferred is that said cone-shaped or tapered cone-shaped surfaces are disposed such that their rotational axes are arranged substantially parallel to the central axis.
It is also especially preferred that the contact surface areas extend at least partially substantially circumferentially relative the central axis.
Also preferred is an arrangement of the contact surface areas in a plane perpendicular to the central axis.
Especially preferred is that the first element form-fit interlocks with the second element by way of the contact surface area so that the first element is essentially non-rotably engaged with the second element upon setting the locking brake.
A non-rotatable coupling between the wheel and the frame is hereby realized when the locking brake is set by means of, for example, an intermeshing gearing arrangement. Said gearing arrangement comprises, for example, an external and an internal gearwheel, wherein upon setting the locking brake, one of said gearwheels engages non-rotatably with the wheel and one of said gearwheels engages non-rotatably with the frame.
The gearing arrangement can, however, also comprise more than, for example, two gearwheels or toothed rings. The gearing arrangement may thus be realized such that when the locking brake is set, a first gearwheel is non-rotatably engaged with the wheel and a second gearwheel is non-rotatably engaged with the frame, wherein a simultaneously engaging shift ring in one of the gearings serves to prevent a relative rotational motion of said gearwheels.
Especially preferred is also that the first and/or the second element has at least one profile projection and the first and/or the second element at least one profile cavity, wherein said at least one profile projection engages respectively into one profile cavity when the locking brake is set so that the first element is non-rotatably coupled relative the second element.
According to a preferred configuration of the present embodiment, the profile projections are formed in the shape of cones or tapering cones, wherein the corresponding profile cavities are essentially formed as contrasting female contours to said profile projections.
This allows for quickly realizing a simple and reliable non-rotatable connection between the wheel and the frame.
According to a particularly preferred embodiment of the present invention, at least one part of said first element with said first contact surface area and/or at least one part of said second element with said second contact surface area is arranged to be axially displaceable relative the central axis at least partially and/or at least intermittently.
It is also further especially preferred that at least one part of at least one of said elements is arranged to be radially displaceable relative the central axis at least partially and/or at least intermittently.
It is preferred that at least one part of said first element with said first contact surface area and/or at least one part of said second element with said second contact surface area is arranged to be circumferentially displaceable relative the central axis at least partially and/or at least intermittently.
It is also preferred to arrange a transfer means between the gearing means and the contact surface areas. Said transfer means converts the signal introduced in the gearing means into a regulated variable for the contact surface areas.
It is particularly preferable that said transfer means is disposed with at least one forced control setting means. This can be realized, for example, in that a spring-loaded means, such as a spoke with a bent end, abuts against a surface profile having an element rotatably arranged thereupon. Upon a corresponding turning movement of said element, the spoke with its bent end shifts axially in correspondence to the current surface structure of the element at the location of the spoke so that the spoke displaces axially in accordance with the surface profile.
According to the present invention, the (switching) signal introduced in the gearing meansxe2x80x94preferably from outsidexe2x80x94can, in principle, be of any type. Said signalxe2x80x94of essentially any typexe2x80x94is convertible by the transfer means into a regulating signal preferably of essentially any type.
The switching signal is, for example, a torque and/or a force substantially parallel to the central axis, and/or a force substantially perpendicular to the central axis, and/or a pivoting motion which, for example, can be executed about an axis perpendicular to the central axis, and/or a helical-like motion. This signal may be introduced as, for example, a tractive force or as a compressive force. The signal is introduced, for example, mechanically, pneumatically, hydraulically, electrically or electromechanically.
The switching signal ensuing from one of said signalsxe2x80x94respectively from a combination of said signalsxe2x80x94is converted by the transfer means into, for example, a regulating signal so that a force substantially parallel to the central axis, and/or a force substantially perpendicular to the central axis, and/or a torque and/or a torque modified with respect to its direction or orientation, and/or a force modified with respect to its direction or orientation, and/or extending in an at least partially radial field relative the central axis.
In addition, this regulating signal itselfxe2x80x94as far as it represents a forcexe2x80x94is also, for example, a tractive or a compressive force. The regulating signal is furthermore of, for example, the mechanical, electrical, electromagnetic, pneumatic or hydraulic type.
It is also preferred that the transfer means has at least two axially displaceable elements disposed opposite one another and in contact with one another at least intermittently, and having cone-like or (tapered) conical surfaces to divert a direction of force. Such an arrangement as comprised by the transfer means enables, for example, that a force directed parallel to the central axis is converted to a force directed perpendicular to the central axis and/or is deviated. A conical configuration to said tapered surfaces allowsxe2x80x94especially when a cone-like outer ring is of multi-sectioned configurationxe2x80x94the generating of, for example, a radial field of force in fundamentally differing radial directions from a force directed parallel to the central axis.
According to an especially preferred embodiment of the present invention, the transfer means is disposed with a spring element for the biasing of the braking means toward a closed position and/or an open position. A spring element of this type enables the contact surface areas which have shifted as a result of actuation of the gearing means, to automatically shift back to their original position upon a rebound movement of said gearing means. The spring element is thus, for example, arranged or pre-tensioned such that the contact surface areas shift to a brake closed position upon actuation of the gearing means and automatically proceed back to a brake opened position upon the rebound movement of the gearing meansxe2x80x94respectively, they return to their original position. It is also particularly preferred for the transfer means to comprise a plurality of cylindrical segment-like shells arranged essentially circumferentially which are stressed in radially inward and/or radially outward directed orientation by a spring element disposed inside of or external said shell arrangement. This enables, for example, the cylindrical segment-like shells to be displaced outwardly from the force directed radially outwardly and then to shift back to their original position following the release of said force due to the effect of the spring force.
It is also preferable for the transfer means to comprise a cylindrical element slotted on at least one circumferential location. Due to, for example, the force of a spring or an O-ring, the element is retained in an essentially closed position. Upon a force being introduced radially from the spring, the cylindrical element widens so that its outer diameter is enlarged.
In accordance with a preferred embodiment of the present invention, the transfer means comprises at least one free wheel element; two counter-rotating shifted free wheel elements is especially preferred. The locking brake can be set via said free wheel elementsxe2x80x94particularly preferably in conjunction with said previously-cited slotted ring.
In a preferred embodiment of the present invention, the gearing means is at least partly configured as an eccentric means, for example as an eccentric selector fork. Said eccentric means comprises, for example, an end portion at which a hole is disposed. Said hole is such arranged, for example, that its center is disposed essentially outside of the longitudinal axis dividing the width dimension in the area of the hole into two uniformly-sized sections. It is also preferred that the spacing between the center of the hole and the longitudinally proximate end of the gearing means deviates by at least one spacing measure which is essentially defined by the center of the hole and a lateral boundary aligned substantially perpendicular to the longitudinal axis of the gearing means. The eccentric member is preferably arranged such that the eccentric hole is positioned essentially over a pin in a first component and comes into contact with a second component on an externally situated contact surface. Particularly preferred is the urging of said second componentxe2x80x94for example, via a spring-loaded actionxe2x80x94against said gearing means. The gearing meansxe2x80x94which preferably displays a constant profile such as a circular or elliptical profile at its end sectionxe2x80x94displaces said first component relative said second component upon a pivotal motion directed about the pin mounting. As a result, an axial force can, for example, be introduced into the transfer means.
Also preferred is that the gearing means, for example a control lever or an eccentric means, turns essentially synchronously with the wheels upon release of the locking brake and a rolling transportation device, such as a wheelchair. This allows the avoiding of a situation in which the user of said transportation device attempts to operate the locking brake while said transportation device is in motion.
Additionally preferred is that the transportation device comprises a latching means for setting the brake in at least one position.
In accordance with an especially preferred embodiment, the transportation device further comprises a free wheel or a double free wheel.
Using aluminum for manufacturing the gearing means and/or the hub and/or the axle and/or the shift ring and/or the threaded ring is preferred. Particularly preferred is the manufacturing of otherxe2x80x94some or even allxe2x80x94structural members out of aluminum.
With all of the previously described embodiments and configurations of the present invention, it is feasible for the braking system to be retrofitted onto an essentially conventional hub. This has the significant advantage that the user can outfit individual wheels according to need.
The task is further solved by the inventive method.
In a method for locking a transportation device, the present invention thus provides the measure of implementing a direct and indirect generation of an essentially non-rotatable connection between a frame and a hub at a position situated external a tire and/or a rim. Said connection is preferably created within the hub.
According to an especially preferred embodiment of the present invention, a method for locking a transportation device is provided.
It should be pointed out that any given combination with respect to the interaction of the individual inventive features is preferred. In particular, the feature combinations disclosed in the independent claims are also preferred even upon omission of one or several respective features.
Furthermore, reference is herewith made to the fact that embodiments of all known arrangements unrelated to specific printed publications are principally known to the applicant, respectively inventor, so that the inventor also reserves protection for same should same not also be publicly known.
It is readily apparent to an expert that there are a number of further feasible modifications and configurations beyond the examples of embodiments of the present invention given herein of which the present invention cover. The invention is in particular not limited to the embodiments as given herein.